Answer:
1/4
Explanation:
I think that you forgot the addition or the subtraction sign between -4x and 5. I will assume that it was an addition sign
3(-4x+5) = 12 Multiply everything in the parentheses by 3
-12x + 15 = 12 Subtract 15 from both sides
-12x = -3 Divide both sides by -12
x = -3/-12 = 3/12 =1/4